Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an mbedtls_ssl_set_session() failure.

The remote Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS host has packages installed that are affected by multiple vulnerabilities as referenced in the USN-8123-1 advisory.

    It was discovered that Mbed TLS incorrectly handled memory allocation failures. A remote attacker could     possibly use this issue to crash the program. This issue only affected Ubuntu 18.04 LTS and Ubuntu 20.04     LTS. (CVE-2021-44732)

    Jonathan Winzig discovered that Mbed TLS incorrectly handled crafted inputs. A remote attacker could     possibly use this issue to crash the program, resulting in a denial of service. This issue only affected     Ubuntu 18.04 LTS, Ubuntu 20.04 LTS, Ubuntu 22.04 LTS. (CVE-2024-23775)

    It was discovered that Mbed TLS incorrectly handled the TLS handshake. A remote attacker could possibly     use this issue to break the security guarantees of the TLS handshake. (CVE-2025-27810)

    Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly documented the behavior of a function.
    Application code relying on the documented behavior might be affected. A remote attacker could possibly     use this issue to execute arbitrary code. (CVE-2025-47917)

    Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly handled crafted input. A remote attacker     could possibly use this issue to crash the program, resulting in a denial of service. (CVE-2025-48965)

    It was discovered that Mbed TLS incorrectly handled a race condition. An attacker could possibly use this     issue to extract AES keys. (CVE-2025-52496)

    Linh Le and Ngan Nguyen discovered that Mbed TLS incorrectly handled certain invalid input. A remote     attacker could possibly use this issue to crash the program, resulting in a denial of service.
    (CVE-2025-52497)

Tenable has extracted the preceding description block directly from the Ubuntu security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 11 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-4236 advisory.

    - -------------------------------------------------------------------------     Debian LTS Advisory DLA-4236-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                       Andrej Shadura     June 30, 2025                                 https://wiki.debian.org/LTS
    - -------------------------------------------------------------------------

    Package        : mbedtls     Version        : 2.16.9-0.1+deb11u1     CVE ID         : CVE-2021-24119 CVE-2021-36647 CVE-2021-43666 CVE-2021-44732                      CVE-2022-46392

    Multiple vulnerabilities have been fixed in mbedtls, a lightweight crypto and     SSL/TLS library.

    CVE-2021-24119

        A side-channel vulnerability in base64 PEM file decoding allows         system-level (administrator) attackers to obtain information about         secret RSA keys via a controlled-channel and side-channel attack on         software running in isolated environments that can be single stepped,         especially Intel SGX.

    CVE-2021-36647

        Function mbedtls_mpi_exp_mod() in lignum.c in Mbed TLS Mbed TLS all         versions before 3.0.0, 2.27.0 or 2.16.11 allowed attackers with access         to precise enough timing and memory access information (typically an         untrusted operating system attacking a secure enclave such as SGX or         the TrustZone secure world) to recover the private keys used in RSA.

    CVE-2021-43666

        In the mbedtls_pkcs12_derivation function an input password's length         is 0 caused a denial of service.

    CVE-2021-44732

        Function mbedtls_ssl_set_session() performed a double free in certain         out-of-memory conditions.

    CVE-2022-46392

        An adversary with access to precise enough information about memory         accesses (typically, an untrusted operating system attacking a         secure enclave) could recover an RSA private key after observing the         victim performing a single private-key operation, if the window size         (MBEDTLS_MPI_WINDOW_SIZE) used for the exponentiation is 3 or smaller.

    For Debian 11 bullseye, these problems have been fixed in version     2.16.9-0.1+deb11u1.

    We recommend that you upgrade your mbedtls packages.

    For the detailed security status of mbedtls please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/mbedtls

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The Linux/Unix host has one or more packages installed that are impacted by a vulnerability without a vendor supplied patch available.

  - Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an     mbedtls_ssl_set_session() failure. (CVE-2021-44732)

Note that Nessus relies on the presence of the package as reported by the vendor.

The remote host is affected by the vulnerability described in GLSA-202301-08 (Mbed TLS: Multiple Vulnerabilities)

  - A Lucky 13 timing side channel in mbedtls_ssl_decrypt_buf in library/ssl_msg.c in Trusted Firmware Mbed     TLS through 2.23.0 allows an attacker to recover secret key information. This affects CBC mode because of     a computed time difference based on a padding length. (CVE-2020-16150)

  - An issue was discovered in Arm Mbed TLS before 2.23.0. Because of a side channel in modular     exponentiation, an RSA private key used in a secure enclave could be disclosed. (CVE-2020-36421)

  - An issue was discovered in Arm Mbed TLS before 2.23.0. A side channel allows recovery of an ECC private     key, related to mbedtls_ecp_check_pub_priv, mbedtls_pk_parse_key, mbedtls_pk_parse_keyfile,     mbedtls_ecp_mul, and mbedtls_ecp_mul_restartable. (CVE-2020-36422)

  - An issue was discovered in Arm Mbed TLS before 2.23.0. A remote attacker can recover plaintext because a     certain Lucky 13 countermeasure doesn't properly consider the case of a hardware accelerator.
    (CVE-2020-36423)

  - An issue was discovered in Arm Mbed TLS before 2.24.0. An attacker can recover a private key (for RSA or     static Diffie-Hellman) via a side-channel attack against generation of base blinding/unblinding values.
    (CVE-2020-36424)

  - An issue was discovered in Arm Mbed TLS before 2.24.0. It incorrectly uses a revocationDate check when     deciding whether to honor certificate revocation via a CRL. In some situations, an attacker can exploit     this by changing the local clock. (CVE-2020-36425)

  - An issue was discovered in Arm Mbed TLS before 2.24.0. mbedtls_x509_crl_parse_der has a buffer over-read     (of one byte). (CVE-2020-36426)

  - An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). The     calculations performed by mbedtls_mpi_exp_mod are not limited; thus, supplying overly large parameters     could lead to denial of service when generating Diffie-Hellman key pairs. (CVE-2020-36475)

  - An issue was discovered in Mbed TLS before 2.24.0 (and before 2.16.8 LTS and before 2.7.17 LTS). There is     missing zeroization of plaintext buffers in mbedtls_ssl_read to erase unused application data from memory.
    (CVE-2020-36476)

  - An issue was discovered in Mbed TLS before 2.24.0. The verification of X.509 certificates when matching     the expected common name (the cn argument of mbedtls_x509_crt_verify) with the actual certificate name is     mishandled: when the subjecAltName extension is present, the expected name is compared to any name in that     extension regardless of its type. This means that an attacker could impersonate a 4-byte or 16-byte domain     by getting a certificate for the corresponding IPv4 or IPv6 address (this would require the attacker to     control that IP address, though). (CVE-2020-36477)

  - An issue was discovered in Mbed TLS before 2.25.0 (and before 2.16.9 LTS and before 2.7.18 LTS). A NULL     algorithm parameters entry looks identical to an array of REAL (size zero) and thus the certificate is     considered valid. However, if the parameters do not match in any way, then the certificate should be     considered invalid. (CVE-2020-36478)

  - A Denial of Service vulnerability exists in mbed TLS 3.0.0 and earlier in the mbedtls_pkcs12_derivation     function when an input password's length is 0. (CVE-2021-43666)

  - Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an     mbedtls_ssl_set_session() failure. (CVE-2021-44732)

  - In Mbed TLS before 2.28.0 and 3.x before 3.1.0, psa_cipher_generate_iv and psa_cipher_encrypt allow policy     bypass or oracle-based decryption when the output buffer is at memory locations accessible to an untrusted     application. (CVE-2021-45450)

  - An issue was discovered in Mbed TLS before 2.28.1 and 3.x before 3.2.0. In some configurations, an     unauthenticated attacker can send an invalid ClientHello message to a DTLS server that causes a heap-based     buffer over-read of up to 255 bytes. This can cause a server crash or possibly information disclosure     based on error responses. Affected configurations have MBEDTLS_SSL_DTLS_CLIENT_PORT_REUSE enabled and     MBEDTLS_SSL_IN_CONTENT_LEN less than a threshold that depends on the configuration: 258 bytes if using     mbedtls_ssl_cookie_check, and possibly up to 571 bytes with a custom cookie check function.
    (CVE-2022-35409)

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The remote Debian 10 host has packages installed that are affected by multiple vulnerabilities as referenced in the dla-3249 advisory.

    -------------------------------------------------------------------------     Debian LTS Advisory DLA-3249-1                debian-lts@lists.debian.org     https://www.debian.org/lts/security/                      Markus Koschany     December 26, 2022                             https://wiki.debian.org/LTS
    -------------------------------------------------------------------------

    Package        : mbedtls     Version        : 2.16.9-0~deb10u1     CVE ID         : CVE-2019-16910 CVE-2019-18222 CVE-2020-10932 CVE-2020-10941                      CVE-2020-16150 CVE-2020-36421 CVE-2020-36422 CVE-2020-36423                      CVE-2020-36424 CVE-2020-36425 CVE-2020-36426 CVE-2020-36475                      CVE-2020-36476 CVE-2020-36478 CVE-2021-24119 CVE-2021-43666                      CVE-2021-44732 CVE-2022-35409     Debian Bug     : 941265 963159 972806 1002631

    Multiple security vulnerabilities have been discovered in mbedtls, a     lightweight crypto and SSL/TLS library, which may allow attackers to obtain     sensitive information like the RSA private key or cause a denial of service     (application or server crash).

    For Debian 10 buster, these problems have been fixed in version     2.16.9-0~deb10u1.

    We recommend that you upgrade your mbedtls packages.

    For the detailed security status of mbedtls please refer to     its security tracker page at:
    https://security-tracker.debian.org/tracker/mbedtls

    Further information about Debian LTS security advisories, how to apply     these updates to your system and frequently asked questions can be     found at: https://wiki.debian.org/LTS     Attachment:
    signature.asc     Description: This is a digitally signed message part

Tenable has extracted the preceding description block directly from the Debian security advisory.

Note that Nessus has not tested for these issues but has instead relied only on the application's self-reported version number.

The version of FreeBSD installed on the remote host is prior to tested version. It is, therefore, affected by a vulnerability as referenced in the c1b2b492-6999-11ec-a50c-001cc0382b2f advisory.

  - Mbed TLS before 3.0.1 has a double free in certain out-of-memory conditions, as demonstrated by an     mbedtls_ssl_set_session() failure. (CVE-2021-44732)

Note that Nessus has not tested for this issue but has instead relied only on the application's self-reported version number.

ID	Name	Product	Family	Severity
304014	Ubuntu 18.04 LTS / 20.04 LTS / 22.04 LTS / 24.04 LTS : Mbed TLS vulnerabilities (USN-8123-1)	Nessus	Ubuntu Local Security Checks	critical
240979	Debian dla-4236 : libmbedcrypto3 - security update	Nessus	Debian Local Security Checks	critical
224125	Linux Distros Unpatched Vulnerability : CVE-2021-44732	Nessus	Misc.	critical
169842	GLSA-202301-08 : Mbed TLS: Multiple Vulnerabilities	Nessus	Gentoo Local Security Checks	critical
169300	Debian dla-3249 : libmbedcrypto3 - security update	Nessus	Debian Local Security Checks	critical
156403	FreeBSD : Mbed TLS -- Potential double-free after an out of memory error (c1b2b492-6999-11ec-a50c-001cc0382b2f)	Nessus	FreeBSD Local Security Checks	critical

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